1. Field of the Invention
The present invention relates to a record/reproduce apparatus, and more particularly to a record/reproduce method which can avoid the defective parts of storage media in record/reproduce operations.
2. Description of the Related Art
Record/reproduce apparatuses include a magnetic disk device, an optical disk device, an optomagnetic disk device, etc. The record media of such record/reproduce apparatuses sometimes contain parts unsuitable for record/reproduce, in other words, medium defects on account of impurities on the record surfaces, etc.
Therefore, a record/reproduce apparatus in the prior art performs a process in which substitutive parts prepared beforehand are used instead of the defective parts.
Such a technique is known from the disclosure of Japanese Patent Application Laid-open No. 315071/1989.
With this technique, one disk surface is reserved as a spare in advance, and sectors on the spare disk surface are substituted for sectors having medium defects on the main disk.
Meanwhile, as information processing has developed highly in recent years, a higher operating speed and a higher reliability are required also of the record/reproduce apparatuses.
In some cases, therefore, a method wherein the k record surfaces of a plurality of record media are accessed in parallel so as to write or read data is adopted. In this specification, such a method shall be termed the "parallel record/reproduce technique".
According to the parallel record/reproduce technique, a plurality of record circuits and reproduce circuits are included in a record/reproduce apparatus, and a plurality of record surfaces are simultaneously accessed by a plurality of magnetic heads so as to write or read data in parallel.
With the record/reproduce apparatus adopting the parallel record/reproduce technique, accordingly, when data composed of a plurality of bits is divided into bit units so as to write or read the resulting bits into or from the plurality of record surfaces, the speed of access to the data can be increased. On the other hand, when the same data is simultaneously written into the plurality of record surfaces in duplicative fashion, recorded data can be multiplexed, and hence, the reliability of the recording can be enhanced.